This invention relates generally to electrochemical batteries, and specifically to high energy electrochemical cells or batteries of the type which employ active metals of groups Ia, IIa and IIIa of the periodic system of the elements.
Heretofore, there have been a number of battery developments utilizing chalcogenide compounds as cathode materials. Exemplary of these prior art batteries are those disclosed in U.S. Pat. Nos. 3,791,867 and 4,000,052 wherein single metal intercalatable dichalcogenides of a layered structure are employed. It has now been discovered that another type of chalcogenide, specifically chalcospinels involving two metals in the form of divalent and trivalent metal ions, may also be utilized as cathode materials with suprisingly good performance. Compounds of sulfur, selenium and tellurium, which ordinarily have cubic face centered structures, have been found to possess the remarkable capability of providing stable and rechargeable cathode materials in the operation of batteries with high faradaic yield per unit weight. Basically, the compounds involve one divalent ion and two trivalent ions of transition metals and four ions of the chalcogen sulfur, selenium or tellurium. Preferred examples of sulfides are CuCo.sub.2 S.sub.4 and CoTi.sub.2 S.sub.4. Preferred selenides include CuCr.sub.2 Se.sub.4 and CoTiSe.sub.4. Useful high energy batteries have been prepared in accordance with the present invention utilizing cathodes containing as the sole cathode-active material one or more compounds selected from this group of chalcogen spinels.